Eliezer and E.T. Jaynes strongly urge seeing probabilities as subjective degrees of certainty that follow fixed laws (an extension of logic). If QBism is supposed to be compatible with this view—and yet not a form of MWI—then where do the complex numbers come from? Do they represent the map or the territory?
A Qbist would say they represent the map. The complex vector formalism of quantum theory is simply a convenient/elegant manual for predicting the outcomes of one’s future interactions with nature. It may be able to tell us something about the territory, but is not the territory itself.
Do you see how that’s not an answer? Why do they work?
A solipsist/Parmenidean theory of reality would need to add another theory, or a copy of all the evidence, in order to make predictions. It would be simpler to drop the solipsism and just state the part of the theory that does the work (which would be our account of reality). Eliezer makes the case that something like a wavefunction exists, and the splitting of ‘worlds’ somehow gives rise to the Born probabilities.
The QBist aim is not to provide an ontological description of the universe. Rather, it is to persuade you that whatever such a description is, quantum theory ain’t it.
“The professed goal is to strip away all those elements of quantum theory that can be interpreted in subjective, agent-dependent terms. The hope is that whatever remains will hint at something essential and objective about nature.”
I’ve read the quantum theoretic parts of the sequences: Eliezer doesn’t really make a case for why Born probabilities arise. Indeed this is one of the major open problems with the MWI.
That’s the basic, some say the only, mystery of MWI: why the world operates according to subjective probability? You’ll find this question posed in the Sequence in some places.
No, that is not the question I asked. The question I asked was what the god-damned imaginary numbers mean, if they aren’t describing reality. Because they don’t look like subjective probability.
Eliezer and E.T. Jaynes strongly urge seeing probabilities as subjective degrees of certainty that follow fixed laws (an extension of logic). If QBism is supposed to be compatible with this view—and yet not a form of MWI—then where do the complex numbers come from? Do they represent the map or the territory?
A Qbist would say they represent the map. The complex vector formalism of quantum theory is simply a convenient/elegant manual for predicting the outcomes of one’s future interactions with nature. It may be able to tell us something about the territory, but is not the territory itself.
Do you see how that’s not an answer? Why do they work?
A solipsist/Parmenidean theory of reality would need to add another theory, or a copy of all the evidence, in order to make predictions. It would be simpler to drop the solipsism and just state the part of the theory that does the work (which would be our account of reality). Eliezer makes the case that something like a wavefunction exists, and the splitting of ‘worlds’ somehow gives rise to the Born probabilities.
The QBist aim is not to provide an ontological description of the universe. Rather, it is to persuade you that whatever such a description is, quantum theory ain’t it.
“The professed goal is to strip away all those elements of quantum theory that can be interpreted in subjective, agent-dependent terms. The hope is that whatever remains will hint at something essential and objective about nature.”
Schlosshauer (https://arxiv.org/pdf/1405.2390.pdf)
I’ve read the quantum theoretic parts of the sequences: Eliezer doesn’t really make a case for why Born probabilities arise. Indeed this is one of the major open problems with the MWI.
That’s the basic, some say the only, mystery of MWI: why the world operates according to subjective probability?
You’ll find this question posed in the Sequence in some places.
No, that is not the question I asked. The question I asked was what the god-damned imaginary numbers mean, if they aren’t describing reality. Because they don’t look like subjective probability.
The existence of some form of subjective probability is perfectly compatible with the existence of some other form of objective probability.